Missing default caddy configuration file?

i got some jail “package” of nextcloud which is using caddy with lets encrypt. I need to remove lets encrypt; because i have other box with nginx that acts as reverse proxy. …

can anyone advice what is default caddy configuration in case i want to run nextcloud on port 80 and my nginx reverse proxy will add certificates and 443?

here is my current caddy conf but i dont think its good … at the moment it shows
root caddy 3559 7 tcp46 *:443 :
root caddy 3559 9 tcp46 *:80 :
but when i setup nginx reverse proxy on top of the caddy 443 it is permanently redirecting and it doesnt work.

thank you!

        # debug
        #acme_ca https://acme-staging-v02.api.letsencrypt.org/directory
        email xxx@pm.me
        default_sni cloxxx.duckdns.org

cloxxx.duckdns.org {
        root * /usr/local/www/nextcloud
        log {
                output file /var/log/cloxxx.duckdns.org.log

        php_fastcgi {
                env front_controller_active true

        tls {
                dns duckdns 90ad2f4b-f57b-4f4b-8094-1b04eba21b82

        header {
                # enable HSTS
                # Strict-Transport-Security max-age=31536000;

        # client support (e.g. os x calendar / contacts)
        redir /.well-known/carddav /remote.php/dav 301
        redir /.well-known/caldav /remote.php/dav 301
        redir /.well-known/webfinger /index.php/.well-known/webfinger 301
        redir /.well-known/nodeinfo /index.php/.well-known/nodeinfo 301



also i found in official repo they are bit mixing caddy and apache together, why?